Ultrastructural characteristics of ostrich eggshell: outer shell membrane and the calcified layers
Journal of the South African Veterinary Association
| Field | Value | |
| Title | Ultrastructural characteristics of ostrich eggshell: outer shell membrane and the calcified layers | |
| Creator | Richards, P.D.G. Richards, P.A. Lee, M.E. | |
| Description | The ultrastructure of the eggshell of the domestic hen has been well researched and structural studies of other avian species, such as the ostrich, often base their interpretation of egg shell structure on that of the chicken. In the ostrich, lowered hatchability and hatching trauma may be due to shell ultrastructural abnormalities. In the present study the ultrastructure of the calcified portion, and the outer shell membrane (OSM), of domesticated ostrich eggshells was investigated using standard electron microscopic techniques. Transmission and scanning electron microscopy studies demonstrated intimate contact between cup-shaped structures present on the OSMand the mammillary layer of the calcified portion of the shell. The initial calcium carbonate growth of the calcified shell was of a dendritic nature with nucleation sites on the surface of the cup's contents. The dendritic growth gave way to a more randomly-orientated, smaller crystallite growth structure, which changed in formas it neared the vertical crystal layer (VCL). The VCL is described as being both amorphous and 'crumbly' depending on the plane of fracture. These observations suggest that firstly, initial calcification is contained within the cups and is then directed outwards to formthe shell and that secondly, the VCL may contain an evolutionary, calcified cuticular layer. These observations serve as a baseline for studies investigating the effect of shell structure and strength on hatchling trauma and the influence of maternal diet. | |
| Publisher | AOSIS | |
| Date | 2000-07-10 | |
| Identifier | 10.4102/jsava.v71i2.687 | |
| Source | Journal of the South African Veterinary Association; Vol 71, No 2 (2000); 97-102 2224-9435 1019-9128 | |
| Language | eng | |
| Relation |
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:
https://jsava.co.za/index.php/jsava/article/view/687/661
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